documentation: Update and fix documentation for --push-peer-info

documentation: Update and fix documentation for --push-peer-info

- description of IV_PROTO was outdated, missing a lot
  of flags
- complete list of compression flags, but separate them out
- various other style/grammar/typo fixes

Change-Id: I7f854a5a14d2a2a391ebb78a2a92b3e14cfd8be6
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <20240206141057.46249-1-frank@lichtenheld.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg28178.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>